Telephone-transmitter



(No Model.)

J. A. BROWN. TELEPHONE TRANSMITTER. No. 504,8131. Patented 391313512, 1.893.

31A/1mm i, @wm

nali A UNITED STATES PATENT OFFICE.

JAMES A. BROVN, OF MOLINE, ILLINOIS.

TELEPHONE-TRANSMITTER.

SLECIFIGATION forming part of Letters Tatent No. 504,801, dated September 12, 1893.

Application filed April 25, 1893. Serial No. 471,800. (No model.)

.To all whom t may concern.-

Be it known that I, J AMES A. BEowN, a citizen of the United States, residing at Moline, in the county of Rock Island and State of Illinois, have invented certain new and useful Improvements in Long-Distance Telephone- Transmitters; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same,reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to certain new and useful improvements in transmitters for electrical telephones, and it has for its object among others to improve upon the construction of this class of devices and to provide a transmitter which is so constructed as to operate upon any line without an induction-coil and regardless of the static condition or resistance of the line.

To this end and to such others as the invention may pertain the same consists in the peculiar construction of thetransmitterhereinafter described, and in novel combination, arrangement and adaptation of parts, all as more fully hereinafter described, shown in the accompanying drawings, and then specifically deiined in the appended claims.

Theinvention is clearly illustrated in the accompanying drawings, which, with the letters of reference marked thereon form a part of this specification, and in which drawings- Figure 1, is a vertical, central section through a telephone transmitter embodying my improvements. Fig. 2 is a rear view of the same.

Reference now being had to the details of the drawings by letter A designates the instrument in its entirety, which in detail consists of the usual case for inclosing the operative parts, and which case for the purpose of more clearly illustrating the operative parts of the device, I have omitted from the drawings, excepting that I have shown the face plate of the case, B, which is provided with the usual convex aperture B which communicates with the vibrating diaphragm or disk C. To the rear face of the part B, is secured a metallic ring or collar D having at its outer edge a flange or extension D. The diaphragm C rests upon the rear face of the body portion D of the ring with its periphery protected by the flange portion D of the ring, and is held securely in place by a supplemental collar or ring E, as shown. Upon one of its sides the flanged portion D of the collar D is provided with a laterally extending arm F, which constitutes the binding-postfor connecting the line or battery.

To the rear face of the diaphragm O is secured an electrode G, which is preferably of cylindrical form as shown and may be constructed of German silver, coin-silver, or of any other conducting material which may be adapted for the purpose. The outer face of this electrode is grained so as to produce a surface made up of innumerable minute points or projections. This grain ed surface I have in the present instance shown as produced by fine lines formed around the electrode, said lines crossing at an angle, thus producing the desired points; but it will be at once evident that a suitable grained surface may be produced in various other ways, such for instance, by etching, dac.

His an electrode which is in all respects similar in form and size to the electrode G just described. This last named electrode is carried at the free end of a spring arm H and is secured to an insulating block I which is attached to the ange D of the collar D. The office of the spring-arm H is to normally hold the electrode H out of engagement with the electrode, and a set screw .I serves as a means for ready adjustment of the same against the electrode I, as may be desired in the adjustment of the instrument for use, as will be readily understood.

Having thus described the details of construction of my instrument, the operation of the same will be readily comprehended by those skilled in the art to which the invention pertains.

It will be seen that the vibration of the diaphragm will be com municated to the electrode carried thereby, thus causing the grained surface of the electrode to rasp across the correspondingly grained surface of the opposite electrode with which it is in contact. It will be understood that the means provided for adjustment of the electrodes in relation to IOO one another is exceedingly sensitive, and when properly adjusted the points upon the adjacent faces of the electrodes will barely contact.

Having thus described my invention, what I claim to be new, and desire to secure by Letters Patent, is

1. The combination with an electric circuit, of a diaphragm and electrodes with grained surfaces, one carried by the diaphragm and the other by a yielding support, the electrodes being arranged substantially at right angles to each other, as specified.

2. In a combination with the diaphragm of a telephone transmitter for transmitting articulate speech, an electrode having a grained surface and adapted to be actuated by the vibration of the diaphragm, to moveiu contact with a second electrode also having a grained surface, substantially as described.

3. In a telephone transmitter, in combination, the diaphragm, the electrodes having grained surfaces adapted to be moved in intermittent contact by the vibrations of the diaphragm and means substantially as described, for adjusting the electrodes relative to one another, substantially as described.

4. In a telephone transmitter, two grained surfaced electrodes at right angles to each other and normally in contact and adapted to be actuated by the Vibration of the diaphragm, substantially as shown and. described.

5. In a telephone transmitter, in combination with the diaphragm, of two electrodes at right angles to each other and having grained surfaces normally in contact and adapted to be actuated by the vibration of the diaphragm, substantially as shown and described and for the purpose specied.

6. A longdistance electric telephone transmitter having two electrodes of any electric conductive material with grained surface in intermittent contact in which the motion of the diaphragm actuates au electric circuit, producing in such circuit a pulsatory current to correspond with the vibrations ot' the voice or any sound, substantially as set forth.

In testimony whereof Iaix my signature in presence of two witnesses.

JAMES A. BROVN.

Vitnesses:

E. S. TRULL, FRANKLIN H. HoUeH. 

